If a secondary consumer receives 50 units of energy from a primary consumer, how much energy did the primary consumer receive from the producers? Assume a 10% energy transfer at each level.

Question

A food chain. Grasses are on the left. To the right of the grasses is an arrow pointing to a beetle. To the right of the beetle is an arrow pointing to a small bird. To the right of the small bird is an arrow pointing to a falcon.

(1 point)
Responses

5 units of energy
5 units of energy

500 units of energy
500 units of energy

50 units of energy
50 units of energy

450 units of energy

Answer 1

In a food chain, there is typically a 10% energy transfer at each trophic level. If we know that the secondary consumer (the small bird, in this case) receives 50 units of energy from the primary consumer (the beetle), we can work backwards to determine how much energy the primary consumer received from the producers (the grasses).

1. Energy at the secondary consumer: 50 units
2. Energy at the primary consumer: Since the energy passes with a 10% efficiency, the energy received by the primary consumer can be calculated using the formula: \[ \text{Energy at primary consumer} = \frac{\text{Energy at secondary consumer}}{0.10} = \frac{50 \text{ units}}{0.10} = 500 \text{ units} \]

So, the primary consumer received 500 units of energy from the producers (grasses).

Thus, the correct response is:

500 units of energy

Answer 2

Scientists are concerned about bee species dying off. They are pollinators, and if they are gone, many plant species will die off because they cannot reproduce. This will cause a population crash. What will happen to biodiversity and sustainability as a result?(1 point)
Responses

Biodiversity will increase, and sustainability will increase.
Biodiversity will increase, and sustainability will increase.

Biodiversity will decrease, and sustainability will increase.
Biodiversity will decrease, and sustainability will increase.

Biodiversity will increase, and sustainability will decrease.
Biodiversity will increase, and sustainability will decrease.

Biodiversity will decrease, and sustainability will decrease.

Answer 3

If bee species are dying off, leading to many plant species being unable to reproduce, this would result in a decline in plant diversity as certain species fail to survive and reproduce. The loss of plant species will ultimately impact the entire ecosystem, affecting all organisms that rely on those plants for food and habitat, which can further decrease biodiversity.

With a decrease in biodiversity, the ecosystem becomes less resilient and less able to sustain itself, leading to decreased sustainability overall.

Therefore, the correct response is:

Biodiversity will decrease, and sustainability will decrease.

Answer 4

Grasses are the dominant producers in the prairie ecosystem. Mice eat the grass seeds, snakes eat the mice, and hawks eat the snakes. Hawks are tertiary consumers.

Remember the 10
percent rule.

How many 500
gram hawks can be supported by 250,000,000
grams of producers?

(1 point)
Responses

50
50

500
500

5,000
5000

150,000

Answer 5

To determine how many 500 gram hawks can be supported by 250,000,000 grams of producers (grasses), we can use the 10% rule of energy transfer throughout the trophic levels.

1. Producers (Grasses): 250,000,000 grams

2. Primary Consumers (Mice): They receive 10% of the energy from the producers: \[ \text{Energy for primary consumers} = 250,000,000 \text{ grams} \times 0.10 = 25,000,000 \text{ grams} \]

3. Secondary Consumers (Snakes): They receive 10% of the energy from the primary consumers: \[ \text{Energy for secondary consumers} = 25,000,000 \text{ grams} \times 0.10 = 2,500,000 \text{ grams} \]

4. Tertiary Consumers (Hawks): They receive 10% of the energy from the secondary consumers: \[ \text{Energy for tertiary consumers} = 2,500,000 \text{ grams} \times 0.10 = 250,000 \text{ grams} \]

5. Number of Hawks: Each hawk weighs 500 grams, so we divide the total energy available for hawks by the weight of each hawk: \[ \text{Number of hawks} = \frac{250,000 \text{ grams}}{500 \text{ grams/hawk}} = 500 \text{ hawks} \]

So, the number of 500 gram hawks that can be supported by 250,000,000 grams of producers is:

500

Answer 6

Decomposers receive 100 units of energy from dead organic matter, and 20 units of energy are released back into the ecosystem. What does this tell us about the role of decomposers in energy transfer?(1 point)
Responses

Decomposers convert most of the energy into biomass and release the rest.
Decomposers convert most of the energy into biomass and release the rest.

Decomposers lose most of the energy as heat, which is why so little is released back.
Decomposers lose most of the energy as heat, which is why so little is released back.

Decomposers transfer all received energy back into the ecosystem.
Decomposers transfer all received energy back into the ecosystem.

Decomposers store all of the energy as they are the end of the food chain.

Answer 7

In the scenario described, decomposers receive 100 units of energy from dead organic matter and release 20 units back into the ecosystem. This indicates that decomposers do not transfer all of the energy they receive back into the ecosystem. Instead, they convert some of the energy into biomass (their own growth and reproduction) and lose a portion of it as heat, which is a common occurrence in energy transfer processes.

Since they are releasing only 20 units out of the 100 units received, this suggests that a significant amount of energy (80 units) is not returned to the ecosystem, likely lost as heat or utilized for metabolic processes.

Therefore, the correct response is:

Decomposers lose most of the energy as heat, which is why so little is released back.

Answer 8

An organism that is classified as anaerobic can perform respiration(1 point)
Responses

with hydrogen only.
with hydrogen only.

without hydrogen.
without hydrogen.

with oxygen only.
with oxygen only.

without oxygen.

Answer 9

An organism that is classified as anaerobic can perform respiration without oxygen. Anaerobic organisms can generate energy through processes such as fermentation, which do not require oxygen to produce ATP (energy).

Therefore, the correct response is:

without oxygen.

Answer 10

How does aerobic respiration differ from anaerobic respiration in the cycling of matter and flow of energy in cells?(1 point)
Responses

Aerobic respiration occurs without oxygen, while anaerobic respiration does require oxygen.
Aerobic respiration occurs without oxygen, while anaerobic respiration does require oxygen.

Aerobic respiration uses oxygen to convert nutrients into energy while anaerobic respiration does not.
Aerobic respiration uses oxygen to convert nutrients into energy while anaerobic respiration does not.

Aerobic respiration stores nutrients without converting them into energy, while anaerobic respiration converts nutrients first.
Aerobic respiration stores nutrients without converting them into energy, while anaerobic respiration converts nutrients first.

Aerobic respiration stores nutrients before converting them, as does anaerobic respiration.

Answer 11

The key difference between aerobic and anaerobic respiration lies in their use of oxygen and how they convert nutrients into energy.

• Aerobic respiration requires oxygen to efficiently convert glucose and other nutrients into energy (ATP) and produces carbon dioxide and water as byproducts.
• Anaerobic respiration, on the other hand, does not require oxygen and typically produces less energy (ATP) compared to aerobic respiration. It can lead to byproducts like lactic acid or ethanol, depending on the type of organism and conditions.

Based on these distinctions, the correct response is:

Aerobic respiration uses oxygen to convert nutrients into energy while anaerobic respiration does not.